In fact, in its raw state, a single sheet of graphene—with no special tweaks or tuning of its properties—provided a frequency response comparable to a pair of commercial Sennheiser earphones. That's pretty good going.

The graphene diaphragm, made by the researchers, is 7 millimeters across but just 30 nanometers thick: insanely thin and light. (Trivia time: a single gram of graphene could cover an entire football field.) That thin sheet was sandwiched between two silicon dioxide electrodes, which allowed it to be driven and to produce sound.

Advertisement

So how come it can keep up with expensive headphones, even on its first iteration? Simple: despite being incredibly light, it's also incredibly strong. A hundred times stronger than steel, in fact. So while regular diaphragms have to be damped so they don't tear themselves to shreds—in turn affecting their audio fidelity—graphene version can pump out beats without any tweaks.

It's worth remembering that these headphone are completely unoptimized, yet still match up to expensive commercial headphones. Tweak the size of the diaphragm, its thickness, and other physical parameters, and the guys at Berkeley could be creating sounds with untold clarity. Just don't ask for the price tag—yet. [arXiv via Extreme Tech]